Cylinder 1 Misfire Detected

What it means

The engine computer noticed that combustion in cylinder 1 is failing, causing a brief slowdown in crankshaft speed on each cycle. The cause is usually a part specific to that cylinder, such as its coil, spark plug or injector.

Symptoms4

• Rhythmic engine shake that is worse at idle.
• Weak pulling power, especially uphill.
• Check engine light on or flashing.
• Occasional hard starting.

Possible causes6

• Weak or failed ignition coil on cylinder 1.
• Worn or cracked spark plug in cylinder 1.
• Clogged or dead fuel injector on cylinder 1.
• Loose or corroded connector on the coil or injector.
• Vacuum leak near the cylinder 1 intake runner.
• Low compression from valve or piston ring wear (less common).

How to diagnose and fix5

1. Swap the cylinder 1 coil with another cylinder; if the code follows, replace the coil.
2. Inspect the spark plug and replace it if worn or fouled.
3. Check the injector connector and listen for its clicking with the engine running.
4. Swap injectors between cylinders if practical to confirm a fault.
5. If the misfire stays on cylinder 1, request a compression test.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

A coil or spark plug usually falls in the lowest tier, but the price rises sharply if low compression requires cylinder head work.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.

Frequently asked questions